GeminiFocus January 2014 | Page 19

to perform critical periodic maintenance on the enclosure shutter drive motors, encoders, gear-boxes, and chains. Figure 2. View from the newly installed Shutter Service Platform at Gemini North, installed to facilitate safety and accessibility during shutter motor servicing. Figure 3 shows the 150-foot telescoping crane used later in the year at Gemini North, which was required to pick up and place the platforms into position. For the crane to safely perform the lift, Gemini had to excavate and grade a level foundation pad and limit the operation to wind speeds less than 20 miles per hour; both items impacted the time and cost of the installation work. Figure 3. A 150-foot telescoping crane was needed to install the Shutter Service Platform. Figures 4-7 (below): Visiting Instruments Clockwise, from top left (all at Gemini South): Gemini’s new visiting-instrument policy, developed jointly by the Observatory and the Science and Technology Advisory Committee (STAC), allows a quick process for bringing a visiting instrument to the telescope on a “once-off” basis. It also allows for the possibility of attracting a wider base of users within the Gemini partnership, who may be interested in the performance potential of these instruments (without going the whole way to facility class, which is a much larger, and likely prohibitive, undertaking). • Installing the base plate of the first platform. • Fleshing out the first platform. • Working on the completed platform. • The installed platforms, looking like they belong there even ahead of painting. The policy (see http://www.gemini. edu/sciops/instruments/visiting-instrument-policy), was put into action with the Differential Spectral Survey Instrument (DSSI); a speckle camera, which Gemini offered in the 2013B Call for Proposals. The instrument was used for eight nights on the telescope in July. Five science programs were observed, including the DSSI team’s own. This plan worked out quite well, with three of the five programs either completed or nearly completed, and two programs more than half completed; the shortfall was due to target position and filter availability, as well as observing conditions, includ- January2014 GeminiFocus 17